Dumb question about Annex Terminal Server

-----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Mouse Sent: Wednesday, May 07, 2014 3:17 PM To: cctalk at classiccmp.org Subject: Re: Dumb question about Annex Terminal Server Well, of course, the most informative answer would be from Steve. But I can offer some speculation (accurate, I hope, but probably worth about what you paid for it). Terminal servers are basically concentrators: they have multiple serial ports, which they multiplex into some kind of data stream over a much faster medium, usually Ethernet. They can be used in either direction; basically, they are a way of putting a whole pile of serial ports on a single machine without needing a lot of serial-port hardware for the machine in question. In this case, my guess would be that a bunch of modems will be connected to the terminal server, so that some small number of hosts (one, probably) can handle that large number of modems without having to find cards for that machine with (what for that hardware is) ridiculously high numbers of serial ports. It's relatively easy to find 16- or 32-port serial cards for a VAX or the like. It's harder for a Sun-3/260. It's even more difficult for an Sbus machine like the SPARCstation-5 he mentioned using. It likely borders on impossible for the NeXT - I can't recall ever even hearing of add-on serial-line hardware for any kind of NeXT (though it probably exists). A terminal server (I don't know why he specified Annex - other people have made them; perhaps he's got some Annex-specific software in mind) allows, effectively, putting all those dozen or so modems on any of those machines relatively easily. Mouse OK, to sound even dumber, when I look at pics on Google for "Annex terminal server", they show boxes with RJ45 connectors. Now, we have MANY 25-pin to RJ45 adapters, so I can understand that. We also have boxes called MUX, CSU, DSU, CSU/DSU, and lots of other acronyms. Some are 9-pin, some are 25-pin, some are BNC, some are AUI, some are RJ45, and some are a combo of two or more. So, since I am stupid about anything except modems, NICs, and hubs/switches, how do I tell what would be useful for this project? Age of this equip ranges from ARK (very old) to fiber optic equip. Cindy